Quake? Not again! It is practically pure FPU test and FPU is softfload (full software emulation) emulated in QEMU. FPU is only important if you want to run ports of PC programs.

Max 2 generations old fastest clock rate possible Intel CPU with at least 2 cores and largest cache is the only correct choice for emulators And do not choose slowest possible memory (1-2 higher speed grade is fine, anything faster is mostly pointless)

You want as good as possible single core performance. Single core emulated CPU performance can't be improved with multiple physical CPU cores. It does not work that way. It can't be parallelized.